1. Field of the Invention
This invention relates to the roadway illuminating art and has particular reference to an improved headlamp system for a motor vehicle.
2. Description of the Prior Art
In an effort to provide maximum illumination of the roadway under various driving conditions without "blinding" the drivers of other vehicles, the automotive industry has traditionally employed a dual-mode headlamp system that provides "low beam" and "high beam" lighting patterns. The "low beam" mode of illumination is used for city driving and on highways where other cars are present, and the "high-beam" mode for driving in rural areas and on turnpikes where glare light is not a problem or does not constitute a safety hazard. Such headlamp systems conventionally employ either two or four headlamps that are selectively energized by suitable switch means in the vehicle to provide the desired high-beam or low-beam modes of illumination. Headlamp systems of both types are well known to those in the art and are presently in use on motor vehicles manufactured in this country and abroad.
A dual-headlamp automotive lighting system having switch means and lamps with light-gate-lens assemblies which permit the lamps to be operated in two or three different lighting modes is disclosed in U.S. Pat. No. 3,617,795 (Peek). Road-lighting systems for vehicles which include four headlamps that are selectively energized to provide low-beam, high-beam and turnpike-beam modes of illumination are described in U.S. Pat. Nos. 3,373,311 (Neulinger et al.) and 3,818,210 (Pitkjaan). A tri-beam roadway-lighting system for motor vehicles which employs four headlamps that provide low-beam, mid-beam and high-beam lighting modes is disclosed in U.S. Pat. No. 3,894,227 (Pitkjaan et al).
Dual-headlamp systems for vehicles having headlamps with various combinations of lens components, baffles and light sources which reduce glare by shifting light rays from one quadrant to another to form overlapping beams, that concentrate the light rays in conical-shaped beams, or which control the light rays with an elongated housing that is fitted with a grooved lens are disclosed in U.S. Pat. Nos. 1,338,675 granted to Churchill; 3,102,692 granted to Einerman and 3,219,809 granted to Bulic.